Chronic Oral Toxicity
Glycols vary considerably in chronic oral toxicity. Propylene glycol (PG) toxicity is especially low in this respect; studies in which rats were provided with drinking water containing as much as 10% propylene glycol over a period of 140 days showed no apparent ill effects. Other investigations have revealed that rats can tolerate up to 4.9% PG in the diet for 24month periods without significant effect on growth rate; however, minor liver damage was observed. Because of its low chronic oral toxicity, PG is generally considered safe for use in foods and pharmaceuticals.
Vapor Inhalation and Eye Exposure
Inhalation of the vapors of propylene glycol (PG) appears to present no significant hazard in ordinary applications. However, limited human experience indicates that breathing of mists of propylene glycols may be irritating to some individuals.
Prolonged inhalation of saturated vapors of PG have produced only minor effects in animals (irritation). However, such concentrations may be irritating to the upper respiratory tract and eyes of humans.
Therefore, breathing spray mists of these materials should be avoided. In general, OMPL does not support or recommend the use of our glycols in applications where breathing or human eye contact with the spray mists of these materials is likely, such as fogs for theatrical productions or antifreeze solutions for emergency eye wash stations.